Table 1:

Technical parameters for different CTA examinations

Scan ParametersProtocol 1: Cerebral Scan with AECProtocol 2: Cervicocerebral Scan without AEC
Topogram120 kV(p), 35 mAs120 kV(p), 60 mAs
Premonitoringa120 kV(p), 40 mAs120 kV(p), 40 mAs
Monitoringb120 kV(p), 40 mAs120 kV(p), 40 mAs
Tube voltage (kV[p])100120
Effective mAs/quality ref. mAs148/160160 (constant tube current)
Pitch factor1.201.20
Rotation time (sec)0.50.33
Acquisition64 × 0.6 mm64 × 0.6 mm
Slice collimation (mm)0.60.6
Section width (mm)4.05.0
Scan range (cm)1941

  • ↵a One section scanned at the level of aortic arch.

  • ↵b Five sections scanned at the level of aortic arch.